JP2001175111A - Device and method for cleaning melting member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To clean a melting member of an electrostatic printer. SOLUTION: A cleaning station 58 for removing toner and fine particles from the melting member contains a first and a second cleaning rollers 259 engaged to the melting member in a rotating state. Respective cleaning rollers have roller surfaces covered with adhesive toner layers. Further respective rollers regulate an internal reservoir part for recovering excess toner and fine particles and have openings forming a fluid path between the reservoir part and the roller surfaces. A synchronizing assembly synchronizes rotations of these rollers so that the second cleaning roller cleans a part of the melting member which is not cleaned by the first cleaning roller due to the surface opening of the first cleaning roller.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for cleaning a melting member of an electrostatic printer.

[0002]

2. Description of the Related Art Electrostatic printers for fusing or fixing a toner image on a substrate to produce a completed document are known. The fusing may be performed after transferring the toner image to the substrate, or the transferring and fusing may be performed simultaneously during the transfuse step. In both configurations, the substrate is fed into the melting nip,
Here, heat and pressure are applied to the toner image by a combination of a fusing member such as a fusing or transfer fixing belt or a roller to fix or fuse the toner image on the substrate. During the fusing step, toner particles from the toner image and substrate debris may adhere to the fusing member. The toner particles and other debris and contaminants can migrate from the fusing member to subsequent documents and cause print defects. Also, the accumulation of toner particles on the fusing member can degrade the fusing quality of the toner image on subsequent documents. The deposition of toner particles may also reduce the operational life of the fusing member.

[0003] Therefore, it is preferable to clean the fusing member to remove other particulate debris such as toner particles, dirt, and fibers which may affect the final print quality.

[0004]

One conventional cleaner uses a cleaning roller that engages the surface of a fuser roll to remove toner particles. The toner particles preferentially adhere to the cleaner roller. However, when excessive toner particles accumulate on the cleaner roller, the toner layer on the surface of the cleaner roller becomes non-uniform, and it becomes impossible to uniformly clean the molten member. Since the toner layer on the cleaner roller may be excessively thick, maintenance for removing excess toner from the toner layer is required.

[0005] In another assembly, the cleaner roller comprises a hollow cylinder having an opening in the cylinder to guide excess toner into the interior from the opening. For this reason, excess toner is collected inside the cylinder,
Prolong the service interval or life of the cleaner roller.
However, this opening creates a gap in the cleaning surface of the roller, and the melter must be cycled multiple times to completely clean the melter surface with the cleaner roller. Thus, the toner particles on the fusing member, as before removal, may hinder fusing or continue to be transferred to subsequent documents.

[0006]

SUMMARY OF THE INVENTION Briefly, a cleaner station according to the present invention has a rotating rack or turret that supports a plurality of cleaner roller assemblies that are capable of engaging a cleaning member with a melting member. The carousel is indexed to position each cleaner roller assembly in sequence and contact the fusing member for cleaning. Each cleaner roller assembly cleans the melted member surface for a preset operating period, such as a predetermined number of pages. At the end of the preset period of operation, the used cleaner roller assembly is disengaged from the fusing member, and the second cleaner roller assembly is engaged with the fusing member for cleaning. In a first embodiment, each cleaner roller assembly comprises a continuous surface or solid surface cleaner roller rotatably mounted on a carousel. The cleaner roller in contact with the fusing member is heated within the adhesion range of the toner used in the printing device. The toner particles and other fine particles such as stains and fibers adhere to the adhesive toner layer formed on the cleaner roller and are removed from the fusing member. The use of a solid surface cleaning roller can effectively clean the melted member in one pass.

In another embodiment of the cleaning station according to the present invention, each cleaner roller assembly comprises:
It has a perforated cleaner roller. Each cleaner roller defines an internal reservoir (storage). The cleaner roller in contact with the fusing member is heated within the adhesion range of the toner used in the printing device. The toner particles and other particulates such as dirt and fibers adhere to the adhesive toner layer and are removed from the fusing member. Excess toner collected on the cleaner roller is forcibly collected in the reservoir, thereby extending the operating life of the perforated cleaner roller.

[0008] In yet another embodiment, each cleaning assembly has a pair of rotatably mounted cleaning rollers. The first cleaning roller along the traveling direction of the melting member is a perforated cleaner roller. The second cleaner roller has a solid surface and is located downstream of the first cleaning roller along the direction of travel. The cleaner roller in contact with the fusing member is heated within the adhesion range of the toner used in the printing device. The toner particles and other particulates such as dirt and fibers adhere to the adhesive toner layer and are removed from the fusing member. The use of at least one solid surface cleaner roller effectively reduces
Cleaning of the melted member is possible in a single pass.

[0009] The cleaner station according to the present invention comprises:
A description will be given together with a fusing member composed of a transfix belt. The cleaner roller is also applicable to other fusing members, such as a transfix roller, a fuser roller, and a fuser belt. Performing the cleaning in a single pass is particularly important in a transfix system where the toner image is periodically transferred to and from the transfix member, and is likely to produce floating toner particles that adhere to the fusing member.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 and 2, a double-sided electrostatographic printer 10 for multicolor cut paper includes an intermediate transfer belt 12. The intermediate transfer belt 12 is advanced on guide rollers 14, 16, 18, and 20, and advances in a traveling direction indicated by an arrow A. For the sake of explanation, it is assumed that one portion of the intermediate transfer member 12 is defined as a toner area.
The toner area is a portion of the intermediate transfer member where various processes are performed by stations arranged around the intermediate transfer member 12. The intermediate transfer member 12 may be provided with a plurality of toner areas, but each toner area is processed similarly.

The toner area is advanced through a set of four toner image forming stations 22, 24, 26 and 28. Each toner image forming station 22, 24, 2
6 and 28 operate to arrange one color toner image on the toner image of the intermediate transfer member 12. Each of the toner image forming stations 22, 24, 26 and 28 operates in the same manner to create a developed toner image and transfer it to the intermediate transfer member 12.

Here, the image forming stations 22, 24, 26 and 28 will be described with respect to the light receiving system.
Those skilled in the art will readily appreciate that ionographic systems and other marking systems can be readily used to form the developed toner image. Each of the toner image forming stations 22, 24, 26 and 28 includes a belt image member 30.
Having. The band image member 30 is a photoreceptor (photoreceptor)
Is a drum or belt that supports

The belt member 30 is uniformly charged at a charging station 32. The charging station has a well-known configuration including a charge generation device such as a corotron or a scorotron that evenly distributes the charge on the surface of the imaging member 30. The exposure station 34 exposes the charged belt member 30 for each image to form an electrostatic latent image in an image area.
For purposes of illustration, the band member defines one image area. The image area is a portion of the band image member where various processes are performed by the stations arranged around the band image member 30. Although a plurality of image areas may be provided in the band image member 30, similar processing is performed on each image area.

Exposure station 34 preferably has a laser that emits a modulated laser beam. Exposure station 34 raster scans the modulated laser beam,
Image on charged image area. Or exposure station 3
4 may form an optical image using an LED array or a structure known in the art, and project the optical image onto the image area of the band image member 30. The exposure station 34 exposes a light image of one color component of the composite color image onto an image area to form a first electrostatic latent image. Each image forming station 22, 24, 26 and 28 forms an electrostatic latent image corresponding to a particular color component of the composite color image.

The image area is advanced to a development station 36. The developing station 36 has a developing device corresponding to the color components of the composite color image. So in general,
Individual toner image forming stations 22, 24, 26 and 28 respectively develop cyan, magenta, yellow and black which make up a typical composite color image. Additional toner image forming stations may be provided for additional or other colors, including highlight colors and other custom colors. Thus, each of the toner image forming stations 22, 24, 26 and 28 develops the component toner image and transfers it to the toner area of the intermediate transfer member 12.
Development station 36 develops the latent image, preferably using charged dry toner powder, to form a developed component toner image. The developing device may use a magnetic toner brush or other known developing structures.

Thereafter, the image area having the component toner image proceeds to a pre-transfer (pre-transfer) station 38. The pre-transfer station 38 preferably has a pre-transfer charging device to charge the component toner image, slightly level the surface voltage on the band member 30, and transfer the component image from the band member 30 to the intermediate transfer member. 12 to facilitate transfer. Alternatively, the pre-transfer station 38 uses the pre-transfer light to
The surface voltage above zero may be leveled. It may also be used with a pre-transfer charging device. Thereafter, the image area advances to a first transfer nip defined between the band member 30 and the intermediate transfer member 12. The band image member 30 and the intermediate transfer member 12 are synchronized so that each has substantially the same linear velocity at the first transfer nip 40. The component toner image is electrostatically transferred from the band image member 30 to the intermediate transfer member 12 using the electric field generating station 42. The electric field generating station 42 is preferably a bias roller, which is electrically biased to generate a sufficient electrostatic field of opposite polarity to the component toner image to transfer the component toner image to the intermediate transfer member 12. Alternatively, the electric field generating station 42 may be a corona device or any other electric field generating system known in the art. Prenip (before nip) transfer blade 44
In this method, the intermediate transfer member 12 is mechanically biased with respect to the band image member 30 to improve the transfer of the component toner image. Thereafter, the toner area of the intermediate transfer member 12 having the component toner image advances from the toner image forming station 22 in the traveling direction.

After the transfer of the component toner image, the band image member 30
Continue moving the image area past the preliminary cleaning station 39. The pre-cleaning station uses a pre-cleaning corotron to adjust the toner charge and the charge of the imaging member 30 so that the image area can be cleaned well. Thereafter, the image area proceeds to the cleaning station 41. The cleaning station 41 removes residual toner particles or debris from the image area. The cleaning station 41 preferably has a blade that wipes residual toner particles from the image area. Alternatively, the cleaning station 41 may use an electrostatic brush cleaner or other known cleaning system. By the operation of the cleaning station 41, each toner image forming station 22, 24, 26
And 28 are completed.

The toner image of the first component in the image area is advanced from the first transfer nip 40 of the image forming station 22 to the first transfer nip 40 of the toner image forming station 24. First transfer nip 4 of toner image forming station 24
Before going to zero, the image adjustment station 46 charges the component toner image uniformly and may transfer a portion of the first component toner image back to the subsequent toner image forming station 24, which may be a floating low charge or reverse charge. Reduces polarity charged toner. An image adjustment station, particularly an image adjustment station before the first toner image forming station 22, also adjusts the surface charge on the intermediate transfer member 12. At each first transfer nip 40, the next component toner image is registered (recorded, registered) with the previous component toner image, and after the last toner image is transferred by the toner image forming station 28,
A composite toner image is formed.

The shape of the interface between the intermediate transfer member 12 and the band image member 30 plays an important role in ensuring good transfer of the component toner image. The intermediate transfer member 12 is moved before the electrostatic image generation area by the electric field generation station 42.
It must make contact with the zero surface, preferably with some pressure, to ensure contact. Generally, it is preferred that the intermediate transfer member 12 winds somewhat around the band member 30 before the nip. Alternatively, a pre-nip pressure blade 44 or other mechanical deflection structure may be provided to form such close pre-nip contact. This contact is an important factor in suppressing the formation of a high electrostatic field in the air gap between the intermediate transfer member 12 and the component toner image in the pre-nip region. For example, when a corotron is used as the electric field generating station 42, the intermediate transfer member 1
2 should preferably contact the toner image in the pre-nip region well before the start of the corona beam profile. When the electric field generating station 42 composed of a bias charging roller is used, the intermediate transfer member 12
Must contact the toner image in the pre-nip area well before the contact nip of the bias charging roller. For all electric field generators, "sufficiently before" means that about 50 .mu.m between the intermediate transfer member 12 and the component toner image.
The electric field in the air gap exceeding m causes the first transfer nip 40
Before the pre-nip region, where the electric field decreases with the pre-nip distance from about 4 volts / μm or less,
Means The drop in the electric field is due in part to the capacitance effect, which depends on various factors. For example, if a bias roller is used, the rate of decrease that varies with distance may be greater if a bias roller with a larger diameter and / or a bias roller with a higher resistivity is used, and / or the insulating layer at the first transfer nip 40. It is the slowest when the capacitance per area is the lowest. The lateral conduction along the intermediate transfer member 12 is:
Depending on the resistivity of the transfer belt and other physical factors, the transfer field area of the prenip may be further extended. When using an intermediate transfer member 12 with a resistivity closer to the lower limit of the preferred range described below, and / or a system using a large bias roller, the longer the contact distance before the nip, the better. Generally, the desired prenip contact distance is about 2 mm to 10 mm when the resistivity is within the desired range and the bias roller diameter is about 12 mm to 50 mm.

The electric field generating station 42 includes a foam material,
Alternatively, a highly compatible bias roller, such as another roller material, whose durometer is effectively very low, ideally less than about 30 Shore A, is preferably used for the first transfer nip 40. In a system that uses a belt for the image forming module, the first transfer nip 40 may optionally relax the component toner image with sound waves to assist in transfer.

In a preferred structure, "slip transfer" is used for color image registration. For slip transfer, the contact zone between the intermediate transfer member 12 and the imaging member 30 is minimized, preferably according to prenip constraints. In this configuration, the post-transfer (post-transfer) contact zone past the electric field generation station 42 is preferably small. Generally, the intermediate transfer member 12 is optionally provided with an electric field in the post nip (post-nip) region provided that a suitable structure is provided to prevent the bias roller from lifting the surface of the imaging member due to the tension of the intermediate transfer member 12. It may be spaced along a suitable bias roller at the generation station 42. In a slip transfer system, the pressure of the bias roller used in the electric field generation station 42 is minimized. The first is to minimize the frictional force acting on the imaging member 30 by minimizing the contact zone and pressure, thereby degrading color registration.
The problem of elastic extension of the intermediate transfer member 12 between the transfer nips 40 is minimized. This also minimizes the kinetic interaction between driving the intermediate transfer member 12 and driving the imaging member 30.

In a slip transfer system, the intermediate transfer member 12 is also generally selected to have a high resistivity in the most preferred range described below, or from the middle to the upper end of the range, to minimize the required prenip contact distance. You have to be. Also, with the slip transfer registration and transfer quality approach, the coefficient of friction of the upper surface material of the intermediate transfer member should be preferentially minimized in order to increase latitude.

In another embodiment, the imaging member 30 such as a photoconductor drum does not have a separate drive, but is instead driven by friction in the first transfer nip 40. That is, the belt image member 30 is driven by the intermediate transfer member 12. Thus, the first transfer nip 40 provides sufficient frictional force on the imaging member by the developer station 36, cleaner station 41, and other subsystems, and to overcome the drag created by supporting the load. . For the belt image member 30 driven by friction, the optimal transfer design considerations are generally opposite to those for slip transfer. For example, the lead of the intermediate transfer member 12 to the first transfer zone is preferably longer in order to maximize the frictional force due to the tension of the intermediate transfer member 12. In the post-transfer zone, the intermediate transfer member 12 is wrapped around the imaging member 30 to further extend the contact zone, thereby increasing the friction drive. Because the pressure increases due to the electrostatic adhesion, it is more beneficial to make the post nip wrap longer than to make the prenip wrap longer. In another embodiment, the frictional force can be further increased by the pressure applied by the electric field generator 42. In such a system, the coefficient of friction of the material of the topmost layer on the intermediate transfer member 12 should ultimately be increased preferentially in order to increase the execution latitude.

Thereafter, the toner area is sent to the subsequent first transfer nip 40. An image adjustment station 46 is provided between the toner image forming stations. The charge transfer in the first transfer nip 40 is usually at least partially due to air breakdown, which is a toner image forming station 22,24,2.
A non-uniform charging pattern may be generated on the intermediate transfer member 12 between 6 and 28. As described below, the intermediate transfer member 12 may optionally have an insulating top layer, in which case the non-uniform charging results in a non-uniform electric field applied in the subsequent first transfer nip 40. This effect accumulates as the intermediate transfer member 12 advances past each subsequent first transfer nip 40. The image adjustment station 46 “levels” the charging pattern on the belt between the toner image forming stations 22, 24, 26, 28 and charges the intermediate transfer member 12 before entering the subsequent first transfer nip 40. Improve pattern uniformity. The image conditioning station 46 is preferably a scorotron, but various other corona devices may be used. As described above, the charge adjustment station 46 is additionally used to adjust the toner charge to prevent re-transfer of toner to subsequent toner image forming stations. If the intermediate transfer member 12 is comprised solely of a semiconductive layer having a resistivity in the desired range described below, the need for the image conditioning station 46 is reduced. As will be described later, even when the intermediate transfer member 12 includes an insulating layer, if the insulating layer is sufficiently thin, the toner image forming station 2
The need for an image adjustment station 46 between 2,24,26,28 is reduced.

It is preferable that the guide roller 14 can adjust the tension of the intermediate transfer member 12. Further guide roller 1
4, an intermediate transfer member 12 that can actively operate the intermediate transfer member 12 in combination with a sensor that detects an edge of the intermediate transfer member 12 and that can deteriorate registration of a component toner image for forming a composite toner image; Reduces wandering across.

Each toner image forming station places a component toner image on a toner area of the intermediate transfer member 12 to form a complete composite toner image. The intermediate transfer member 12 advances the composite toner image from the last toner image forming station 28 to the pre-transfer charge adjusting station 52. If the intermediate transfer member 12 has at least one insulating layer, the pre-transfer charge adjustment station 52
The electric charge in the toner area is leveled. The pre-transfer charge adjusting station 52 is used to adjust the toner charge for transfer to the transfer fixing member 50. It is preferably composed of a scorotron, but may be of various corona devices. A second transfer nip 48 is defined between the intermediate transfer member 12 and the transfer fixing member 50. The electric field generating station 42 and the pre-transfer nip blade 44 engage the intermediate transfer member 12 next to the second transfer nip 48 and perform the same function as the electric field generating station and the pre-transfer blade 44 adjacent to the first transfer nip 40. I do. However, the electric field generation station at the second transfer nip 48 may be slightly stiffer to engage a compatible transfix member 50. The composite toner image is electrostatically transferred to the transfer and fixing member 50 with the aid of heat.

The electrical properties of the intermediate transfer member 12 are also important. The intermediate transfer member 12 may optionally have a single-layer structure or a multilayer structure. In each case, the electrical properties of the intermediate transfer member 12 are preferably selected to reduce the high voltage drop across the intermediate transfer member. To reduce high voltage drops, the backside layer of intermediate transfer member 12 preferably has a sufficiently low resistivity. Also, the electrical properties and transfer structure must be selected to prevent high electrostatic transfer fields in the pre-nip region of the first transfer nip 40 and the second transfer nip 48. If the prenip electric field in the air gap, typically about> 50 μm, between the component toner image and the intermediate transfer member 12 is high, image degradation due to toner transfer across the air gap and prenip air breakdown This can lead to image defects. This can be avoided by bringing the intermediate transfer member 12 into early contact with the component toner image before the electric field generating station 42, as long as the resistivity of any layer of the intermediate transfer member 12 is sufficiently high. The intermediate transfer member 12 must also have a sufficiently high resistivity of the top layer to prevent very high currents from flowing through the first transfer nip 40 and the second transfer nip 48. Finally, the intermediate transfer member 12 and system design need to minimize the high and / or non-uniform charge accumulation that can occur on the intermediate transfer member 12 between the first transfer nips 40.

The preferred material for the single layer intermediate transfer member 12 is a "charge relaxation time" that is the same or shorter than the dwell time between toner image forming stations.
e) ", and more preferably the" nip relaxation time (ni) which is the same as or shorter than the dwell time of the transfer nip.
p relaxation time). Here, the “relaxation time” refers to a characteristic time during which the voltage drop across the thickness of the intermediate transfer member is attenuated. Dwell time is the time that a basic portion of transfer member 12 spends passing through a given area. For example, the dwell time between the image forming stations 22-24 is obtained by dividing the distance between the image forming stations 22-24 by the traveling speed of the transfer member 12. The dwell time of the transfer nip is determined by the electric field generation station 42.
The width of the contact nip formed under the influence of
Divided by the speed of travel.

The "charge relaxation time" is a relaxation time during which the intermediate transfer member is substantially isolated from the influence of the capacitance of other members in the transfer nip 40. Generally, the charge relaxation time applies to the area before or after the transfer nip 40. This is the dielectric constant k of the physical quantity of the material layer and the resistivity ρ
When a classical "R-C time constant" Rokeiipushiron ₀ which is the product of the dielectric constant epsilon ₀ of vacuum. In general, the resistivity of a material can change due to the applied electric field in the material. Here, the resistivity should be determined by the applied electric field corresponding to about 25-100 volts applied to the layer thickness. "Nip relaxation time"
Is a relaxation time in an area such as the transfer nip 40. 42
Is a corona electric field generator, the "nip relaxation time" is almost the same as the charge relaxation time. However, if a bias transfer device is used, the nip relaxation time is generally longer than the charge relaxation time. This is because not only the capacitance of the intermediate transfer member 12 itself, but also the surplus capacitance per unit area of the insulating layer existing in the transfer nip 40 is affected. For example, the capacitance per unit area of the photoconductor coating on the belt member 30 and the capacitance per unit area of the toner image are:
Affects nip relaxation time. For illustrative purposes, C _L is the capacitance per unit area of the layer of the intermediate transfer member 12, C _L
tot indicates the total capacitance per unit area of all the insulating layers other than the intermediate transfer member 12 in the first transfer nip 40. If the electric field generation station 42 is a bias roller, the nip relaxation time is the charge relaxation time multiplied by the quantity [1+ (C _tot / C _L )].

Under the conditions of the resistivity range defined in the above description, a high voltage drop applied to the intermediate transfer member 12 during the transfer of the component toner image at the first transfer nip 40 can be avoided.
To avoid high prenip fields, the lateral or advancing volume resistivity of the intermediate transfer member must not be too low. All that is required is that the lateral relaxation time of the charge flow to and from the electric field generating station 42 in the first transfer nip 40 be longer than the dwell time lead of the first transfer nip 40. Reads during dwell time are in volume L / v. L is the distance from the pre-nip area where the intermediate transfer member 12 and the component toner image first contact to the start position of the electric field generation station 42 in the first transfer nip 40. The quantity v is the speed of travel. The lateral relaxation time is determined by the lateral resistance along the belt between the electric field generating station 42 and the pre-nip area of the first contact, and the intermediate transfer member 1.
2 and toner image forming stations 22, 24, 26, 28
Is proportional to the total capacitance C _tot per area of the insulating layer in the first transfer nip 40 between the image forming member 30 and the substrate. A useful equation for estimating a suitable resistivity range to avoid unwanted high pre-nip fields near the field generating station 42 is [ρ _L VLC _tot ]> 1. This amount is called the "transverse resistivity" of the intermediate transfer member 12, and is the volume resistivity of the member divided by the thickness of the member.
If the electrical properties of member 12 are not isotropic, the volume resistivity of interest to avoid high pre-nip fields is the resistivity in the direction of travel of the layer. When the resistivity depends on the applied electric field, the lateral resistivity is about 500 to 1500 vol.
It should be determined at an electric field of ts / cm.

Thus, the preferred resistivity range of the single layer intermediate transfer member 12 is determined by the system structure, transfer member thickness, travel speed, and capacitance per unit area of various materials in the first transfer nip 40. And so on. For a wide range of common system configurations and traveling speeds, the preferred resistivity of a single layer transfer belt is generally less than about 10 ¹³ ohm-cm, more preferably less than about 10 ¹³ ohm-cm.
10 ¹¹ ohm-cm. A preferred lower limit for the resistivity is generally a transverse resistivity greater than about 10 ⁸ ohms / square, more preferably generally greater than about 10 ¹⁰ ohms / square. As an example, for a typical intermediate transfer member 12 thickness of about 0.01 cm, 10 ¹⁰ ohms / square
A lateral resistivity greater than e corresponds to a volume resistivity greater than 10 ⁸ ohm-cm.

In the following description, a preferable range of electrical characteristics of the transfer fixing member 50 that enables good transfer at the second transfer nip 48 will be specified. The transfix member 50 is preferably comprised of multiple layers, and the electrical properties selected for the top layer of the transfix member 50 affect the preferred resistivity of the single layer intermediate transfer member 12. If the top layer of the transfix member 50 has a sufficiently high resistivity, typically greater than about 10 ⁹ ohm-cm, the lower limit of the preferred resistivity of the single layer intermediate transfer member 12 described above applies. . If the top layer of the transfuse member 50 has a somewhat lower resistivity than about 10 ⁹ ohm-cm, in order to avoid problems in the transfer of the second transfer nip 48 occurs, the single layer intermediate transfer The lower limit of the preferred resistivity of member 12 must be increased. The transfer problem includes an unnecessary high current flowing between the intermediate transfer member 12 and the transfer fixing member 50, and deterioration of the transfer due to a decrease in the transfer electric field. If the resistivity of the top layer of the transfix member 50 is less than about 10 ⁹ ohm-cm, a preferred lower limit for the volume resistivity of the single layer intermediate transfer member 12 is typically about 1
0 ⁹ ohm-cm or more.

In addition, the intermediate transfer member 12 is provided with toner image forming stations 22, 24,
It must have sufficient lateral stiffness to avoid registration problems between 6,28. The rigidity is
This is the sum of the product of the Young's modulus multiplied by the layer thickness for all the layers of the intermediate transfer member. The preferred range of stiffness depends on various system parameters. The value required for rigidity is
It increases as the amount of frictional drag at and / or between the toner image forming stations 22, 24, 26, 28 increases. Suitable stiffness also
It increases as the length of the intermediate transfer member 12 between toner image forming stations increases and as the requirements for color registration increase. Preferred stiffness is> 8
00PSI-inches, more preferably> 2000P
SI-inches.

A preferred material for the single-layer intermediate transfer member 12 is a polyamide that provides good electrical control via a conductive control additive.

The intermediate transfer member 12 may optionally have a multilayer structure. The backside layer opposite the toner area is preferably semiconductive within the range described. Multi-layer intermediate transfer member 1
Suitable materials for the second back layer are the same as those described for the single-layer intermediate belt 12. Within limits, the top layer may optionally be "insulating" or semi-conductive. Each case has advantages and disadvantages.

By way of illustration, if the relaxation time of the charge flow is much longer than the dwell time of interest,
The layer on the intermediate transfer member 12 can be considered "insulating". For example, the nip relaxation time of a layer in the first transfer nip 40 may be partially changed.
This layer is "insulating" during the dwell time in the first transfer nip 40 if it is significantly longer than the time required to pass through. If the charge relaxation time of a layer is significantly longer than the dwell time required for part of the layer to travel between toner image forming stations, then the layer will
It is insulative between 2,24,26,28. On the other hand, if the relaxation time of a layer is equal to or less than the appropriate dwell time, then the layer is semiconductive in the sense described herein. For example, if the nip relaxation time is shorter than the dwell time in the first transfer nip 40, the layer is semi-conductive during the dwell time of the first transfer nip 40. Further, the intermediate transfer member 1
Image forming station 2
If less than the dwell time between 2,24,26,28, this layer is semi-conductive during the dwell time between toner imaging stations. The formula for determining the relaxation time of the upper surface layer on the intermediate transfer member 12 is substantially the same as that described above for the single-layer intermediate transfer member. Thus, whether a layer on the multilayer intermediate transfer member 12 is "insulating" or "semi-conductive" during a particular dwell time of interest depends not only on the electrical properties of the layer, but also on the rate of travel. , System structure, and layer thickness.

The layer of the transfer belt is generally "insulating" in most transfer systems if the volume resistivity is generally greater than about 10 ¹³ ohm-cm. The insulating top layer on the intermediate transfer member 12 causes a voltage drop across the layer, thus reducing the voltage drop across the composite toner layer in the first transfer nip 40. Thus, the presence of the insulating layer is to form the same electrostatic field that acts on the charged composite toner image,
Higher voltages need to be applied in the first and second transfer nips 40,48. This voltage requirement is governed primarily by the "dielectric thickness" of such an insulating layer, that is, the actual thickness of the layer divided by the dielectric constant of the layer. One of the possible drawbacks of the insulating layer is that if the sum of the dielectric thicknesses of the insulating layer on the intermediate transfer member 12 is too large, good electrostatic transfer of the component toner image may occur on the intermediate transfer member 12. Unnecessarily high voltage is required. This is particularly true for the intermediate transfer member 1
"Insulating" over dwell time longer than one revolution
For a color imaging system having a layer of
Each of the electric field generating stations 4
The charge is accumulated by the charge transfer of No. 2. Due to this charge accumulation, in order to transfer the subsequent component toner image well,
A higher voltage is required on the back surface of the intermediate transfer member 12 at the subsequent electric field generation station 42. To completely neutralize this charge between the first transfer nips 40 using the corona device of the image adjustment station 46, the intermediate transfer member 12
The charge of the transferred composite toner image is unnecessarily neutralized or, in some cases, reversed in polarity. Therefore, to eliminate the need for unacceptable high voltage on the back surface of the intermediate transfer member 12, the total dielectric thickness of such insulating top layer on the intermediate transfer member 12 is preferred for good and stable transfer performance. Must be kept thin. An acceptable total dielectric thickness may be as high as about 50 μm, with a preferred value being <10 μm.
m.

The optimal uppermost layer of the intermediate transfer member 12 is
It preferably has good toner release characteristics such as low surface energy, and preferably has low affinity for oils such as silicone oil. Examples of desirable overcoat materials having good toner release characteristics are PFA, TEFLON®, and various fluoropolymers. One of the advantages of applying an insulating coating on the semiconductive backside layer of the intermediate transfer member 12 is that a material with good toner release characteristics is more likely without the constraint that the coating material must also be semiconductive. It is easy to use. Another possible advantage of a high resistivity coating applies to embodiments that desire to use a transfix member 50 where the resistivity of the top layer is as low as << 10 ⁹ ohm-cm. As described above, the resistivity of the single-layer intermediate transfer member 12 is approximately 10 ⁹
If it is less than ohm-cm, it is preferably generally about >> to avoid transfer problems in the second transfer nip 48.
Limited to 10 ⁹ ohm-cm. In a multilayer intermediate transfer member 12 where the resistivity of the top layer is preferably sufficiently high,> 10 ⁹ ohm-cm, the resistance of the backside layer may be low.

The advantage of the semiconductive coating on the intermediate transfer member 12 is that the imaging stations 22, 24, 26,
Before or during the period 28, the charge leveling for leveling the charge on the intermediate transfer member 12 is unnecessary. Another advantage of the semiconductive coating on the intermediate transfer member is that the top layer can be much thicker than with an insulating coating. The ranges of the charge relaxation conditions and the corresponding resistivity conditions required to realize these advantages are the same as those described above for the back surface layer. In general, the semiconductive region of interest will have a charge relaxation time of the toner image forming station 2
The resistivity is less than the dwell time spent between 2,24,26,28. In a more preferred resistivity configuration, the layer can be thicker, and this configuration can cause the first transfer nip 40
During the nip relaxation time, a part of the intermediate transfer member 12
This is a range of the resistivity such that the dwell time required to pass through the transfer nip 40 is shorter. In such a preferred resistivity region, the voltage drop of the layer at the end of the transfer nip dwell time is small due to the charge conduction of the layer.

The restrictions on the lower resistivity limit with respect to the lateral resistivity apply to the semiconductive top layer, any semiconductive middle layer, and the semiconductive back layer of the multilayer intermediate transfer member 12. . The preferred range of resistivity for each of these layers is:
This is almost the same as that described above for the single-layer intermediate transfer member 12. Further resistivity constraints on the transfer problem during the second transfer nip 48 include the multilayer intermediate transfer member 1
Applies to the top two layers. Preferably, the resistivity of the top semiconductive layer of the intermediate transfer member 12 is such that the resistivity of the top layer of the transfix member 50 is typically 10 ⁹ ohm-cm.
If it is slightly lower, it should generally be> 10 ⁹ ohm-cm.

The transfer of the composite toner image in the second transfer nip 48 is performed by transfer assisted by a combination of static electricity and heat. The electric field generating station 42 and the guide roller 74 are electrically biased to electrostatically transfer the charged composite toner image from the intermediate transfer member 12 to the transfer fixing member 50.

The transfer of the composite toner image at the second transfer nip 48 is such that the temperature of the transfix member 50 is maintained at a sufficiently high optimum level and the temperature of the intermediate transfer member 12 is significantly lower before entering the second transfer nip 48. If maintained at an optimal level, it can be heat assisted. The mechanism of the heat assisted transfer is considered to be the softening of the composite toner image during the dwell time of the toner contact at the second transfer nip 48. The softening of the toner is caused by contact with the transfer fixing member 50 having the higher temperature. This softening of the composite toner enhances the adhesion of the composite toner image to the transfer fixing member 50 at the interface between the composite toner image and the transfer fixing member. This is also
The adhesion of the layered toner pile of the composite toner image is increased.
The temperature on the intermediate transfer member 12 before entering the second transfer nip 48 must be sufficiently low to avoid excessive toner softening and excessive toner adhesion to the intermediate transfer member 12. The temperature of the transfix member 50 must be significantly above the toner softening point before entering the second transfer nip to obtain optimal thermal assistance in the second transfer nip 48. Further, the temperature of the intermediate transfer member 12 immediately prior to the second transfer nip 48 must be significantly lower than the temperature of the transfix member 50 for optimal transfer at the second transfer nip 48.

The intermediate transfer member 12 before the second transfer nip 48
Is important to maintain good transfer of the composite toner image. When the temperature of the intermediate transfer member 12 is optimally increased,
With the transfer fixing member 50 at a lower temperature, the second transfer nip 4
The composite toner image necessary for thermally assisting the electrostatic transfer of No. 8 can be softened as desired. However, there is a risk that the temperature of the intermediate transfer member 12 becomes too high and excessive softening of the composite toner image occurs on the intermediate transfer member before the second transfer nip 48. In this situation, the composite toner image is transferred to the intermediate transfer member 12.
Unnecessarily strongly, and the second transfer may be deteriorated. Preferably, the temperature of the intermediate transfer member 12 prior to the second transfer nip 48 is maintained below or within the Tg (glass transition temperature) of the toner.

The transfer fixing member 50 includes guide rollers 74 and 7
6,78,80 to the circulation path. The guide rollers 74, 76 are preferably heated alone or together to heat the transfix member 50. The intermediate transfer member 12 and the transfix member 50 are preferably synchronized to have approximately the same speed in the transfer nip 48. Further heating of the transfix member is provided by heating station 82. Heating station 82 is preferably comprised of a far-infrared lamp located inside the path defined by transfix member 50. Alternatively, the heating station 82 may be a heated shoe that contacts the backside of the transfix member 50, or another heat source located inside or outside the transfix member 50. The transfer fixing member 50 and the pressure roller 84 define a third transfer nip 86 therebetween.

The release agent applicator 88 applies a controlled amount of release agent, such as silicone oil, to the surface of the transfix member 50. The release agent assists in releasing the composite toner image from the transfix member 50 in the third transfer nip 86.

The transfer fixing member 50 is preferably composed of a plurality of layers. The transfer fixing member 50 is provided in the second transfer nip 4
8 must have appropriate electrical characteristics so that a high static electric field can be generated. Preferably, the transfix member 50 has electrical characteristics that allow the voltage drop across the transfix member 50 in the second transfer nip 48 to be sufficiently low so that excessively high voltages may not be required. . Further, the transfer and fixing member 50 includes the intermediate transfer member 12 and the transfer and fixing member 50.
It is preferred to ensure an acceptable low current between The requirements for the transfix member 50 depend on the characteristics selected for the intermediate transfer member 12. That is, the transfer fixing member 5
0 and the intermediate transfer member 12, the second transfer nip 48
It has a sufficiently high resistance inside.

The transfix member 50 preferably includes a laterally rigid backside layer, a compatible thick rubber intermediate layer,
And has a thin outermost layer. The thickness of the backside layer is preferably greater than about 0.05 mm. The thickness of the intermediate conforming layer and the outermost layer preferably total more than 0.25 mm, more preferably more than about 1.0 mm. The back layer and the intermediate layer need to have sufficiently low resistivity so that the voltage requirements in the second transfer zone 48 are not too high. Suitable resistivity conditions follow those described above for intermediate transfer member 12. In other words, the resistivity ranges suitable for the back layer and the intermediate layer of the multilayer transfer fixing member 50 are such that the nip relaxation time of these layers in the electric field generation area of the second transfer nip 48 is different from the electric field generation area of the second transfer nip 48. Must be less than the dwell time spent in. The equations for the nip relaxation time and the nip dwell time are almost the same as those described for the single-layer intermediate transfer member 12. Therefore, the specific resistivity range suitable for the back layer and the intermediate layer depends on the configuration of the system,
It depends on the layer thickness, the speed of travel, and the capacitance per unit area of the insulating layer in the transfer nip 48. In general, the volume resistivity of the backside and intermediate layers of the multilayer transfuse member 50 is typically about 10 ¹¹ ohm for most systems.
Less than -cm, it must be more preferably less than about 10 ⁸ ohm-cm. Optionally, the backside layer of the transfix member 50 may be of high conductivity, such as metal.

As with the multilayer intermediate transfer member 12, the top layer of the transfix member 50 may optionally include a transfer nip 48.
"Insulating" during the dwell time (typically> 10 ¹² o
hm-cm) or the transfer nip 4
8 and semiconductive (generally 10 ⁶ to 10 ¹² ohm-c
m). However, if the top layer becomes insulating, the dielectric thickness of this layer is preferably small enough to avoid excessively high voltages. Preferably, for such an insulating top layer, the dielectric thickness of the insulating layer is generally less than about 50 μm, more preferably about 10 μm.
m. When an insulating top layer having a very high resistivity is used, the charge relaxation time is longer than the circulation time of the transfer fixing member, and charges are accumulated on the transfer fixing member 50 due to the movement of charges in the transfer nip 48. Thus, a circulating discharge station 77 such as a scorotron or other charge generation device is required to control and reduce the level of periodic charge accumulation.

The transfix member 50 may have an additional intermediate layer. Generally, the additional interlayer having a dielectric thickness greater than about 10 μm preferably has a sufficiently low resistivity to reduce the voltage drop across the additional interlayer.

The transfer fixing member 50 is preferably made of a material having a low surface energy, for example, silicon elastomer, Vito.
It has a top layer composed of a fluoroelastomer such as n.RTM., polytetrafluoroethylene, perfluoroalkane, and other fluorinated polymers. The transfix member 50 preferably includes an intermediate layer configured to have desired electrical properties by adding carbon or other conductivity enhancing additive to Viton® or silicon to form an upper layer and a lower layer. Hold between. The back layer is preferably a fabric that has been modified to have the desired electrical properties. Alternatively, the back layer may be a metal such as stainless steel.

The transfix member 50 may optionally be a transfix roller (not shown) or is preferably in the form of a transfix belt. The transfix member is more compact than the transfix belt in the transfix member 50,
Further, the present invention is superior in that the driving and operating requirements necessary for improving the moving quality in the color system are simplified. However, the transfix belt has a longer life,
It is superior to the transfer fixing roller in that the substrate can be peeled off and the periphery can be lengthened in order to reduce the replacement cost.

The intermediate layer of the transfix member 50 is preferably thicker to increase its conformity to the coarser substrate 70, and
To expand the range of substrate latitude that can be used with Furthermore, the thickness is more than about 0.25 mm, preferably 1.0 m
The use of a relatively thick intermediate layer, greater than m, results in creep that improves document release from the output of the third transfer nip 86. In another embodiment, a thick low durometer compatible interlayer and top layer, such as silicon, on the transfix member 50 is used to allow for a lower image gloss with a more forgiving transfix system.

Before the second transfer nip 48, the transfer fixing member 50
A relatively high upper temperature is advantageous for transfix systems. The transfer step in the second transfer nip 48 includes:
The single color toner layer of the composite toner image and the laminated multilayer color toner layer are simultaneously transferred. The transfer of the toner layer closest to the interface with the transfer belt is the most difficult.
Depending on the color toner layer to be transferred in any particular area, a given separated color toner layer may be closest to the intermediate transfer member 12 surface or may be away from the surface. For example, if the magenta toner layer is the last stack deposited on the transfer belt, the magenta layer may be in direct contact with the surface of the intermediate transfer member 12 in some color printing areas, or cyan and / or in other color areas. Alternatively, it may be laminated above the yellow toner layer. If the transfer efficiency is very low, most of the color toner adjacent to the intermediate transfer member 12 will not be transferred, but most of this color toner layer laminated on another color toner layer will be transferred. For this reason, for example, when the transfer efficiency of the composite toner image is not so high, the composite toner image area where the cyan toner is in direct contact with the surface of the intermediate transfer member 12 is more likely to be the composite toner image where the cyan toner layer is on the yellow toner layer. The transfer of the cyan toner layer is worse than the image area. Second transfer nip 48
Medium transfer efficiency is> 95%, preventing significant color shift.

FIG. 7 shows experimental data on the relationship between the amount of residual toner left on the intermediate transfer member 12 and the temperature of the transfer fixing member 50. Curve 90 is with electric field, pressure and heat assisted, and curve 92 is without electric field assisted but with pressure and heat assisted. A very low residual toner amount means that the transfer efficiency is very high. The toner used in the experiment has a glass transition temperature Tg of about 55 ° C. Substantial thermal assistance is observed when the temperature of the transfix member 50 exceeds Tg. When an electric field is applied, and the temperature of the
Operating above about 165 ° C., well above the g range,
Almost 100% of toner transfer occurs. Desirable temperatures depend on toner characteristics. In general, for a number of different toners and system conditions, it has been found that operation at temperatures significantly above Tg is advantageous to thermally assist electrostatic transfer.

The transfer and fixing member 50 in the second transfer nip 48
If the temperature is too high, a problem may occur due to excessive toner softening on the intermediate transfer member side of the composite toner layer. Therefore, the second
The temperature of the transfer fixing member 50 before the transfer nip 48 must be controlled within an optimum range. Second transfer nip 48
The optimum temperature of the composite toner image in the middle is lower than the optimum temperature of the composite toner image in the third transfer nip 86. Second transfer nip 4
8, the desired temperature of the transfix member 50 for heat assist is easily obtained, while preheating the substrate 70 reduces the desired higher toner temperature required for more complete toner fusion in the third transfer nip 86. Can be achieved. Transfer / fixing to the substrate 70 is controlled by the temperature of the interface between the substrate and the composite toner image. As a result of the thermal analysis, the interface temperature
It is shown that the temperature rises with the temperature rise of both the transfer fixing member 50.

When the temperature of the transfer fixing member 50 is substantially constant in the second transfer nip 48 and the third transfer nip 86, the optimum transfer temperature in the second transfer nip 48 is controlled by adjusting the temperature of the intermediate transfer member 12. And the third transfer nip 86
Transfer fixation during is optimized by preheating the substrate 70. Alternatively, for certain toner compositions or operating regions, preheating of the substrate 70 is not required.

The substrate 70 is transferred to the substrate preheater 73 by the material supply and registration system 69 and registered. Substrate preheater 73 preferably comprises a transport belt that carries the substrate onto a heated platen. Alternatively, the substrate preheater 73 may be constituted by a group of heated rollers forming a heating nip therebetween. The substrate 70 is sent to the third transfer nip 86 after being heated by the substrate preheater 73.

FIG. 8 shows the relationship between the magnitude of fixing called crease and the temperature of the transfer fixing member 50 for different substrate preheating temperatures. Curve 94 is for a preheated substrate and curve 96 is for a substrate at room temperature. As can be seen from the results, at the same fixing level,
As for the temperature of the transfixing member 50, the curve 94 having a higher substrate preheating temperature is a curve 96 having a lower substrate preheating temperature.
Much lower than that. When the substrate 70 is heated by the substrate preheater 73 before the third transfer nip 86, the temperature of the transfer fixing member 50 can be optimized for improving the transfer of the composite toner image at the second transfer nip 48. In this way, the temperature of the transfix member 50 can be controlled to a desired optimal temperature range for optimal transfer in the second transfer nip 48, including the temperature of the substrate 70 in this controlled transfix. Member 5
At a temperature of 0, the temperature is controlled to a correspondingly high required temperature required for good fixing and transfer to the substrate 70 in the third transfer nip 86. Therefore, it is not necessary to cool the transfer fixing member 50 before the second transfer nip 48 for optimal transfer in the second transfer nip 48. That is, the transfer fixing member 50 can be maintained at substantially the same temperature in both the second transfer nip 48 and the third transfer nip 86.

Further, since the transfer / fixing member 50 does not need to be cooled substantially before the second transfer nip 48, the layer covering the transfer / fixing member 50, the intermediate layer, and the uppermost layer are relatively thick, which is preferable. Can be thicker than about 1.0 mm.
Since the intermediate layer and the top layer of the transfix member 50 are relatively thick, compatibility can be improved. Transfer fixing member 5
A high conformity of 0 allows for printing on a wider latitude of the substrate without substantially degrading the print quality.
That is, the composite toner image can be transferred onto the relatively rough substrate 70 with higher efficiency.

Further, the temperature of the transfer fixing member 50 is preferably substantially the same at both the second transfer nip 48 and the third transfer nip 86. However, the temperature of the composite toner image is preferably higher in the third transfer nip 86 than in the second transfer nip 48. Accordingly, the temperature of the substrate 70 in the third transfer nip 86 is higher than the temperature of the intermediate transfer member 12 in the second transfer nip 48. Alternatively, the transfix member 50 can be cooled prior to the second transfer nip 48, but the temperature of the transfix member 50 is preferably maintained at a temperature well above the Tg of the composite toner image, as described above.
Further, under certain operating conditions, the top layer of the transfix member 50 may be heated before the second transfer nip 48.

The composite toner image is transferred and fused to the substrate 70 in the third transfer nip 86 to form a completed document 72.
Substrate 70 and transfer fixing member 5 in third transfer nip 86
0 and the pressure roller 8 against the guide roller 76
4 to transfer the composite toner image to the substrate 70.
We fuse. The pressure in the third transfer nip 86 is preferably between about 40 psi and 500 psi, more preferably about 60 psi.
~ 200 psi. The transfix member 50 and the pressure in the third transfer nip 86 and the appropriate durometer of the transfix member 50 cause creep in the third transfer nip to transfer the composite toner image and substrate 70 to the transfix member 50.
To help release. Preferred creep is greater than 4%.
Peeling is further aided by the positioning of guide roller 78 relative to guide roller 76 and pressure roller 84. The guide roller 78 is positioned so that a small amount of the transfer fixing member 50 is wound around the pressure roller 84.
The arrangement of the guide rollers 76 and 78 and the pressure roller 84 forms a third transfer nip 86 having a high pressure zone and a low pressure zone adjacent thereto in the traveling direction. The width of the low pressure zone is preferably 1 to 3 times the width of the high pressure zone, more preferably about 2 times. The low pressure zone effectively adds an additional 2-3% of creep to promote delamination. Peeling is further assisted by providing a peeling system 87, preferably an air puffing system. Alternatively, release system 87 may be a release blade or other known system for releasing documents from rollers or belts. The pressure roller may be replaced by another pressure applicator such as a pressure belt.

After peeling, the document 72 proceeds to a selectively durable polishing station 110 and then to a sheet stocker or other well-known document application system (not shown). The printer 10 may also have a duplex printing function that advances the document 72 to the inverter 71, reverses the document 72 and resends it to the pre-transfer heating station 73 to print on the back of the document 72.

The cooling station 66 is provided for the intermediate transfer member 1
2 is cooled after the second transfer nip 48 in the traveling direction. The cooling station 66 preferably transfers some of the heat on the intermediate transfer member 12 at the outlet side of the second transfer nip 48 to the second transfer nip 48.
The transfer nip 48 is moved to the heating station 64 on the entrance side. Alternatively, the cooling station 66 is connected to the second transfer nip 4
A part of the heat on the intermediate transfer member 12 on the exit side of the transfer member 8 is transferred to the substrate before the third transfer nip 86. Alternatively, a plurality of heating stations 64 and cooling stations 66 may be used to realize heat sharing to increase heat transfer efficiency.

The cleaning station 54 engages with the intermediate transfer member 12. Cleaning station 54
Preferably removes oil that may accumulate on the intermediate transfer member 12 from the transfix member 50 at the second transfer nip. For example, if a suitable layer of silicon is used for the top layer of the transfix member 50, some silicone oil contained in the silicon material will be transferred from the transfix member 50 to the intermediate transfer member 1.
2 and finally the band image member 39 is contaminated. further,
The cleaning station 54 also removes residual toner remaining on the intermediate transfer member 12. The cleaning station 54 also removes oil deposited on the transfix member 50 by the release agent management system 88 that may contaminate the imaging member 30. The cleaning station 54 is preferably a single cleaning blade, or one with an electrostatic brush cleaner, or a cleaning web.

The cleaning station 5 according to the invention
Reference numeral 8 (see FIG. 3) engages with the surface of the transfer fixing member 50 after passing through the third transfer nip 86, and removes residual toner and contaminants from the surface of the transfer fixing member 50. The cleaning station 58 includes a plurality of cleaner roller assemblies 2.
Rotatable turret or carousel 2 supporting 81
80. The cleaner roller assembly 281 includes:
Engage with the transfer fixing unit 50 in the cleaning state. The cleaner roller assembly is mounted on a rotatable turret or carousel. The carousel is indexed to sequentially engage each cleaner roller assembly with the fusing member for cleaning. First
In the embodiment, each cleaner roller assembly 281
Consists of a rotatable solid surface cleaner roller 259. The cleaner roller 259 is provided for the transfer fixing member 5.
The transfix member 50 is oriented so as to be orthogonal to the direction of travel and preferably extends over substantially the entire width of the transfix member 50. The cleaner roller 259 preferably comprises a metal tube or cylinder. Alternatively, the cleaner roller may be constructed from cardboard or other high surface energy material. The partially melted toner forms a toner layer on the outer surface of the cleaner roller 259. The toner layer becomes adhesive or tacky as the temperature increases. The cleaner roller 259 of the cleaner roller assembly in contact with the fusing member is heated within the adhesion range of the toner used in the printing device. By using the cleaner roller 259 having a solid surface, the transfer fixing member 50 can be effectively cleaned in one pass. The cleaner roller 259 is preferably an idler roller that is not driven but generates a rotational movement from frictional engagement between the toner layer 262 and the transfer fixing member 50.

The cleaner roller 259 is supported at a predetermined fixed distance from the surface of the transfer fixing member 50. The cleaner roller 259 is the transfer fixing member 5
It is held in contact with the surface of the zero by pressure. The cleaner roller 259 is preferably located on the opposite side of the guide roller 80. Alternatively, the pressure roller 261 may be arranged on the opposite side of the first cleaner roller 259 to maintain an appropriate pressure between the transfer fixing member 50 and the cleaner roller 259. The cleaner roller 259 is rotatably engaged with the transfer fixing member 50, and
Apply a pressure of ５０50 psi.

The cleaner roller 259 is preferably made of a rigid material such as steel, but may be copper, aluminum stainless steel, cardboard or the like. Cleaner roller 2
59 is preferably heated by the transfix member 50;
Thereby, the toner layer 26 on the cleaning roller 259 is
2 is maintained in a partially molten state. Alternatively, the toner layer may be heated by an external heater. The operating temperature range of the toner layer 262 is a sufficiently high temperature for melting the toner, generally 10
It is higher than 0 ° C. If the temperature of the toner layer is too low, toner and other contaminants cannot adhere to the cleaner roller 259. The temperature range of the toner layer 262 must not be raised to temperatures above 180 ° C. to prevent separation of the toner layer. The partially melted toner is thus preferably 100-180 ° C.
Is maintained within the optimum temperature range. The toner layer 262 is maintained within the optimum temperature range by the heat from the transfer fixing member 50 and, if necessary, the additional heating from the cleaning heater 265.

The cleaner roller 259 is preferably first covered with a toner layer 262. After that, the toner layer 262
Is heated until it is within the optimal temperature range. Alternatively, the cleaner roller 259 does not have a toner layer from the beginning, and is in a bare state when it comes into contact with the transfer fixing member 50. When the cleaner roller 259 is heated within the optimum range, the toner particles from the transfer fixing member 50 adhere to the cleaner roller 259. Thus, the toner layer 262 is formed from the excessive toner particles on the transfer fixing member 50. Also, other particles and contaminants on the transfix member 50 adhere to the tacky toner layer on the cleaner roller 259 and are removed from the transfix member.

The cleaner roller 259 preferably has a solid surface, and cleans the surface of the transfer fixing member for a preset operation period, for example, for a preset number of pages.
At the end of the preset operation period, the used cleaner assembly 281 is disengaged from the transfer fixing member in the cleaning state, and the second cleaning assembly 281 is engaged with the melting member 50 in the cleaning state. In most operating environments, the cleaning station 5
8 cleans the transfix member 50 in a single pass and prepares the transfix member 50 to receive a new composite toner image.

The cleaning station 5 according to the invention
8, each cleaner roll assembly 281 has perforated cleaner rollers 260 instead of solid surface rollers 259 (see FIG. 5). Perforated cleaner roller 260 is a tube or a hollow cylinder that defines an internal reservoir (storage) 264. The perforated cleaner roller 260 has an opening 266 passing through the roller surface.
Opening 266 may be a series of holes, or a single helically wound cut, preferably extending axially along the length of perforated cleaner roller 260.

The adhesive toner layer is maintained on the perforated cleaner roller 260 as described above. When the thickness of the toner layer 263 increases due to accumulation of toner particles from the transfer fixing member 50, excess toner is removed from the perforated cleaner roller 26.
0 into the internal reservoir 264. Excess toner from the toner layer 263 is moved into the internal reservoir 264 by the pressure between the perforated cleaner roller 260 and the transfer fixing member 50. The openings 266 squeeze or move excess toner from the toner layer 263 into the internal reservoir 264 of the cleaner roller 260, thereby maintaining a suitable thickness of the toner layer 263 on the surface of the cleaner roller 260. As a result,
Excess toner and particulates accumulate in the internal reservoir 264, and the operating life of each cleaner assembly 281 and thus the cleaning station 58 between routine services.
Extend the overall operating life. This opening forms a cleaning gap where cleaning of the transfix member is not performed as the opening passes over the surface of the transfix member.

In yet another embodiment of the present invention, each cleaning assembly 281 has a solid surface cleaner roller 259 and a perforated cleaner roller 260 (see FIG. 6) rotatably mounted at intervals. The perforated cleaner roller 260 is disposed first in the traveling direction of the transfer fixing member. Solid surface cleaner roller 259
Is disposed downstream from the perforated cleaner 260 in the traveling direction. The cleaner rollers 260 and 259 can be engaged with the transfer fixing member 50 in a cleaning state. The first perforated cleaner roller 260 and the second solid surface cleaner roller 259 correspond to the perforated cleaner roller 2 described above.
It functions in the same manner as 60 and the solid surface cleaner roller 259. Since the perforated cleaner roller 260 accumulates excess toner and fine particles in the internal reservoir 264,
The operating life is slightly longer. However, the perforated cleaner roller 26
A value of 0 generally means that the opening 266 cannot clean the entire surface of the transfer fixing member 50 in one pass. The solid surface cleaner 259 generally cleans the entire surface of the transfix member 50. Solid surface cleaner roller 2
59 denotes a case where the perforated cleaner roller 260 is
The operation life is long because most of the toner and fine particles contaminating 0 are removed. Therefore, the cleaner roller assembly 281 can clean the transfer fixing member in one pass and has a relatively long operating life. Performing the cleaning in a single pass is particularly important in a transfix system where the toner image is periodically transferred to and from the transfix member and where there is a high probability that the floating toner particles will adhere to the transfix member. . Operational life is further extended by contacting the unused cleaner roller assembly with the transfix member by operation of the turret. As the operating life of the cleaning assembly is extended, less routine maintenance is required.

The transfer fixing member 50 is carried in the circulation path by the pressure roller 84. Alternatively, a driving force is obtained by driving the guide roller 74, or the driving force is increased. The intermediate transfer member 12 is preferably driven by pressure contact with the transfix member 50. Intermediate transfer member 1
2 is driven by the intermediate transfer member 12 and the transfer fixing member 50.
Is obtained from the driving force of the transfer fixing member 50 by utilizing the adhesive contact between Due to this adhesive contact, the transfer fixing member 50 and the intermediate transfer member 12 are separated from each other by the second transfer nip 48.
Move in synchronization with each other. Due to the adhesive contact between the intermediate transfer member 12 and the toner image forming stations 22, 24, 26, 28, the intermediate transfer member 12 causes the toner image forming stations 22, 24, 2 in each first transfer zone 40.
It moves in synchronization with 6,28. Accordingly, the toner image forming stations 22, 24, 26, 28
2 can be driven by the transfer fixing member 50. Alternatively, the intermediate transfer member 12 may be driven independently. When the intermediate transfer member is driven independently, a movement buffer (not shown) engaging with the intermediate transfer member 12
And serves to buffer the relative movement between the transfer and fixing member 50. The motion buffer system includes a tension system with a feedback and control system, independent of the irregularities of the motion transferred to the intermediate transfer member 12 at the second transfer nip 48, and the intermediate transfer in the first transfer nip 40. Maintain good movement of the member 12. The feedback and control system may include a registration sensor that detects movement of the intermediate transfer member 12 and / or movement of the transfix member 50 to provide registration timing for transferring the composite toner image to the substrate 70.

The polishing station 110 is preferably located downstream from the third transfer nip 86 in the direction of travel and selectively enhances the gloss characteristics of the document 72. The polishing station 110 has opposing fusing members 112, 114 defining a polishing nip 116 therebetween. Polishing nip 116 is adjustable so that polishing can be selected. In particular, these fusing members are cam driven, so that the transfix nip can be a glossy
2,114 wide enough to allow the document to pass through with little contact. When the operator selects polishing, the fusing members 112 and 114 are cammed into a pressure relationship and driven to increase the gloss level of the document 72 passing through the polishing nip 116. The amount of polishing can be selected by the operator by adjusting the temperature of the melting members 112 and 114. The higher the temperature of the melting members 112 and 114, the greater the amount of polishing. U.S. Pat. No. 5,521,688, entitled "Hybrid Color Fuser", which is incorporated herein by reference, describes a polishing station that uses a radioactive fuser.

It is advantageous in operation that the fixing function and the polishing function are separated. The separation of the fusing and polishing functions allows the operator to select a suitable level of gloss on the document 72. To achieve high polished performance in a color system, the temperature in the third transfer nip 86 generally must be relatively high. Also, in general,
In order to avoid the problem of abrasion that causes unevenness in gloss due to a change in the surface roughness of the transfix member due to abrasion, a material having high heat resistance and abrasion resistance such as Viton (registered trademark) is also required on the transfix member 50. is there. The high temperature requirements and the use of high heat and abrasion resistant materials generally necessitate increased oil coverage by the release agent management system 88. In a transfix system such as printer 10, elevated temperatures and increased oil levels on transfix member 50 can cause photoreceptor 30 contamination problems. Printers that have a transfix system and require high gloss use either thick, incompatible transfix members or relatively thin transfix members. However, somewhat incompatible transfix members and relatively thin transfix members lack the high compatibility required for good printing on coarse paper stock or the like.

The use of the polishing station 110 reduces or eliminates the need to create a gloss at the third transfer nip 86. The reduction or elimination of the need for polishing in the third transfer nip 86 minimizes surface wear problems of the color transfix member material and makes it easier to use silicon or other similar soft transfix member material. , A long-life transfer fixing member 50 can be obtained. This also allows the use of a relatively thick layer on the transfix member 50, thereby extending the operational life of the transfix member material and increasing the suitability for image formation on coarse-grained substrates. This also lowers the temperature requirements of the transfix member, further extending the life of the transfix material, and significantly reducing the oil requirements in the third transfer nip 86.

The polish station 110 is preferably located sufficiently close to the third transfer nip 86 to take advantage of the temperature rise of the document 72 that occurs in the third transfer nip 86. The elevated temperature of the document 72 reduces the operating temperature required for the polishing station 110. The lower temperature of the polishing station 110 improves the life and reliability of the polishing material.

The use of a highly compatible silicone transfix member 50 is an example of an important means of achieving low gloss and good operational fusing latitude. The important parameters are that the durometer of the top layer of the transfix member 50 is sufficiently low, preferably rubber, and that the intermediate layer of the transfix member 50 is relatively thick, which is also preferred. Is made of rubber. Suitable durometer ranges depend on the thickness of the composite toner layer and the thickness of the transfix member 50.
A preferred range is about 25-55 Shore A, generally about 3
5-45 Shore A is preferred. Thus, suitable materials include many silicon material compositions. Transfer fixing member 5
The thickness range of the layer covering 0 is preferably greater than about 0.25 mm,
More preferably, it is more than 1.0 mm. For low gloss,
Extends toner release life, increases compatibility with rough substrates,
Thicker layers are generally preferred to increase nip dwell time and allow for good document release. In an optional embodiment, to reduce the transfix gloss, the surface of the transfix member 50 is slightly roughened to increase the tolerance of the rigidity of the transfix member. Particularly with high durometer materials and / or thin layers, there is a tendency to reproduce the surface texture of the transfix member. Therefore, if the surface of the transfer fixing member 50 is slightly rough, the gloss tends to decrease even if the rigidity is high. The surface gloss number of the transfix member is preferably <30 GU.

It has been demonstrated that under conditions where the mass per area of the toner is relatively high, the range of operating temperatures for obtaining good fixing and low gloss during transfer fixing is narrow. For a toner about 7 μm in size, where the required toner mass is about 1 mg / cm ² , the transfix member 50 required to achieve a gloss level <30 GU and an acceptable crease level of less than 40
Temperature is 110-120 ° C, paper preheating is about 85 ° C
It is. However, when the mass per area of the toner is low, the operating temperature range of the transfer fixing system for fixing and low gloss is widened. The use of a small pigment-rich toner in combination with a compatible transfix member 50 reduces the mass per area of toner in the color system and provides an operating temperature range for low gloss in the third transfer nip 86. Spread out. Required toner mass is about 0.4mg / c
For a toner having a size of about 3 μm having a size of m ² , a gloss level <30
To achieve a GU and less than an acceptable crease level 40, the required temperature of the transfix member 50 must be between 110 and 150.
° C and the preheating of the paper is about 85 ° C.

The polishing system 110 preferably comprises a Vi
ton (registered trademark). Or other options for polishing after transfix,
Teflon.RTM. Thin sleeve / overcoating on a rigid roller or belt, or a hard fused member with such overcoating applied to a rubber underlayer. Fusing members 112, 11
The topmost fixing layer of No. 4 is preferably harder and has a higher level of surface smoothness than that used for the topmost layer of transfix member 50 (surface gloss is preferably> 50 GU, more preferably > 70 GU). Alternatively, the top surface may be textured to give the document 72 a texture. Polishing station 110 preferably includes a release agent management application system (not shown). The polishing station further includes a release mechanism, such as an air puffer, to assist in releasing the document 72 from the fusing members 112,114.

Optionally, the toner composition may include a wax to reduce the oil requirements of the polishing station 110.

The polishing station 110 is connected to the printer 10 having the intermediate transfer member 12 and the transfer fixing member 50.
Described in combination with
10 is applicable to all printers having a transfix system that produces low gloss documents 72. In particular, this can include a transfix system that uses only one transfer / transfix member.

As an example of the system, the transfer fixing member 50
Is preferably 120 ° C. in the third transfer nip 86,
Substrate 70 is preheated to 85 ° C. As a result, a document 72 having a gloss value of 20 to 30 GU is obtained. The melt is preferably heated to 120 ° C. Fusing members 112, 114
Is preferably adjustable so that different degrees and levels of gloss can be applied to different print runs depending on operator choice. Higher temperatures of the fusing members 112 and 114 promote polishing, while lower temperatures reduce the amount of polishing on the document 72.

The fusing members 112 and 114 are preferably fusing rollers, but may be fusing belts. Each melting member 112,1
The top surface of 14 is slightly incompatible, preferably about 55
It has a durometer of more than Shore A. The polishing station 110 performs polishing after passing through the printer 10 using a transfix system that operates with low gloss in the third transfer nip 86. Printer 10 produces document 72 having 10 to 30 Gardner gloss units (GU), preferably after third transfer nip 86. The gloss on the document 72 varies depending on the toner mass per unit area. Polishing device 11
0 preferably gives the gloss of the document 72 to the SD Warren Company
Raise to more than about 50 GU on Lustro Gloss® paper from the company.

[Brief description of the drawings]

FIG. 1 is a schematic side view of an electrostatographic printer for double-sided cut paper having a cleaning station according to the present invention.

FIG. 2 is an enlarged schematic side view of a transfer nip of the printer of FIG.

FIG. 3 is an enlarged view of a schematic side sectional view of the cleaning station of FIG. 2;

FIG. 4 is an enlarged schematic view of a cleaner roller assembly of the cleaning station 58.

FIG. 5 is an enlarged schematic view of another embodiment of the cleaner roller assembly of FIG. 3;

FIG. 6 is an enlarged schematic view of still another embodiment of the cleaner roller assembly of FIG. 3;

FIG. 7 is a graph showing the relationship between the residual toner and the temperature of the transfer fixing member.

FIG. 8 is a graph showing the relationship between the crease and the temperature of the transfer fixing member for a predetermined substrate temperature.

[Explanation of symbols]

Reference Signs List 10 printer, 12 intermediate transfer member, 50 transfer fixing member, 58 cleaning device, 259 first cleaning roller, 260 second cleaning roller, 261
Pressure roller, 262 toner layer, 264 internal reservoir,
266 aperture, 281 cleaner roller assembly.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Gerald M. Fletcher United States Pitts Ford Carriage Court 19, New York 19 (72) Inventor John Es Barks United States Webster Hidden Valley Trail 1137

Claims (3)

[Claims] 1. A cleaning device for a fusing member, which is rotatably engageable with a fusing member, has a first roller surface, has a first internal reservoir, the first roller surface, and the first roller surface. A first cleaning roller defining a first opening for fluid connection with an internal reservoir of the first roller, an adhesive first toner layer on the surface of the first roller, and a rotatable member for the melting member. A second cleaning surface having a second roller surface and defining a second internal reservoir and a second opening fluidly connecting the second roller surface and the second internal reservoir. Roller, an adhesive second toner layer on the surface of the second roller, synchronizing rotation of the first cleaning roller and rotation of the second cleaning roller, A cleaning roller adjacent to the first opening of the fusing member; A cleaning device that includes a synchronizer assembly to clean the pass. 2. A fusing station having a cleaning device, comprising: a fusing member, a first cleaning surface engaged with the fusing member in a cleaning state, having a first cleaning surface, and defining a first cleaning gap. A first cleaning member in which the melting member is not cleaned by the first cleaning member in the first cleaning gap; and a second cleaning surface that engages with the melting member and has a second cleaning surface. A second cleaning member that defines a cleaning gap of the first cleaning member and a rotation of the first cleaning member and the second cleaning member are synchronized with each other so that the second cleaning surface is the first cleaning surface of the melting member. Synchronizer assembly for cleaning the area adjacent to the gap No melting station. 3. A method of cleaning a molten member by a cleaning device, wherein the cleaning device comprises a first member.
A first cleaning roller having a cleaning surface for defining a first cleaning gap; a first toner layer having an adhesive on the first cleaning surface; and a second cleaning device having a second cleaning surface. A second cleaning roller defining a gap; and an adhesive second toner layer on the second cleaning surface, the method comprising: moving the melting member in a traveling direction; A first cleaning roller rotatably contacting the fusing member to clean the fusing member with the first cleaning toner layer and defining an uncleaned portion of the fusing member at the first cleaning gap; Contacting the second cleaning roller rotatably with the melting member. And synchronizing the first cleaning roller and the second cleaning roller to clean portions of the fusing member where the second toner layer is not cleaned.